Adherence to pharmacotherapy in bipolar disorder patients with and without co-occurring substance use disorders.

OBJECTIVE

To examine patterns of adherence to mood stabilizers and reasons for nonadherence in patients with bipolar disorder, with and without substance use disorder (SUD).

METHOD

From December 2003 to October 2004, 115 patients with DSM-IV-diagnosed bipolar disorder (58 with SUD and 57 without SUD) were administered a structured interview regarding their lifetime experience with mood stabilizers.

RESULTS

Lifetime adherence with mood stabilizers for the SUD group was 65.5%, versus 82.5% for the non-SUD group (p < .05). Lifetime lithium adherence for the SUD group was lower than for the non-SUD group (65.9% vs. 85.0%, p < .05). Substance-related reasons were more commonly cited by the SUD group than the non-SUD group. In contrast, pill- and dosage-related reasons were more frequently endorsed by the non-SUD group than the SUD group.

CONCLUSION

In bipolar disorder patients, those with co-occurring SUD were less adherent than those without SUD. The SUD group was also less adherent to lithium than the non-SUD group. The reasons for nonadherence differed by presence or absence of a SUD. Physicians should be alert to these differences in their clinical practices while prescribing medications.